The present invention relates to a pneumatic tire and a tire mold used for curing and molding the pneumatic tire, and more particularly, to a pneumatic tire and a tire mold which can inhibit a land in a tread surface from chipping and cracking.
Conventionally, for example, there are pneumatic tires including a tread surface having lands which comprise ribs defined by circumferential grooves extending in a circumferential direction of the tire, and sipes disposed in the lands at predetermined intervals along the tire circumferential direction, each of the sipes extending in a widthwise, direction of the tire with only one end thereof being open to a circumferential groove (see Unexamined Japanese Patent Application Publication No. 5-178018, for example).
The pneumatic tires having ribs with these sipes are generally cured and molded using a sectional type tire mold having an annular side mold section with a tread forming surface for forming a tread surface which is composed of a plurality of sectors into which the side mold section is divided along its circumferential direction, instead of using a tire mold consisting of two mold-halves, thereby preventing the lands from chipping and land parts located at the sipe ends from cracking.
However, merely using the sectional type tire mold, chipping and cracking can not effectively prevented and may often occur, due to rubber materials employed for a tire tread. Especially, these drawbacks are apt to occur in the vicinity of sector divisional positions.